diff --git a/pkg/dev_compiler/analysis_options.yaml b/pkg/dev_compiler/analysis_options.yaml
index b2a090c..007c3e7 100644
--- a/pkg/dev_compiler/analysis_options.yaml
+++ b/pkg/dev_compiler/analysis_options.yaml
@@ -22,6 +22,7 @@
     - curly_braces_in_flow_control_structures
     - empty_constructor_bodies
     - library_names
+    - no_duplicate_case_values
     - null_closures
     - prefer_contains
     - prefer_equal_for_default_values
diff --git a/pkg/dev_compiler/lib/src/compiler/js_names.dart b/pkg/dev_compiler/lib/src/compiler/js_names.dart
index 24d3dbd..ba120a3 100644
--- a/pkg/dev_compiler/lib/src/compiler/js_names.dart
+++ b/pkg/dev_compiler/lib/src/compiler/js_names.dart
@@ -289,7 +289,6 @@
     case "import":
     case "in":
     case "instanceof":
-    case "let":
     case "new":
     case "return":
     case "super":